[ExI] [Extropolis] DIY Quantum Protection for Bitcoin

[John Clark]

On Mon, Jun 1, 2026 at 2:34 PM Stuart LaForge <avant at sollegro.com> wrote:


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> *> Ok, so I think I have come up with a simple low technology method of
> safeguarding bitcoin against Quantum computing algorithms like Shor's.First
> you need to but 2 hardware cold wallets (e.g. Trezor, Ledger, etc.) Create
> a seed phrase to generate a public key with one of them and send your BTC
> to it.When you want to spend or transfer bitcoin, you set up (or reset) a
> seed phrase on your second wallet. Spend whatever bitcoin you need to and
> then transfer the remaining balance to the second wallet. When you
> spend/send bitcoin, the public key of the sending wallet gets exposed on
> the blockchain in a way that a quantum computer could use it to crack the
> private key for the spending wallet, so the idea is to empty that wallet
> completely. The public key of the receiving wallet is kept secret because
> it does not show up anywhere during the transaction. The only private key
> that a quantum computer could derive would be for the empty wallet that you
> no longer use.Then when you want to spend/send money from your second
> wallet, factory reset the original wallet and create a new seed phrase for
> it to generate a novel public. Spend your bitcoin from the second wallet
> and immediately send the remaining balance to the, now reset 1st wallet
> that has a brand new seed phrase / public key that has never been exposed
> on the blockchain and cannot be used to hack your private key.*
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> *Then, when you want to perform another transaction, rinse and repeat.
> Always resetting and reseeding the unused wallet to get a fresh public key
> before use. With two hardware wallets, you should be able to keep this up
> indefinitely. It is a little bit of a hassle, but from what I understand of
> the bitcoin protocol, it should keep your bitcoins safe from quantum
> computing algorithms with existing technology. Let me know if you find a
> weakness in this scheme.*


*Keeping the public key unexposed is a well known defense and it does offer
a little protection but the trouble is the public key isn't just exposed
when you initiate a transaction, it's exposed from the moment the
transaction hits the holding area where unconfirmed transactions wait in a
decentralized queue before being processed by miners, depending on how busy
the network is that could be anywhere from a few minutes to a few hours*,
and* in the quantum world *that is a* long time*;* a sufficiently powerful
quantum computer could crack your private key faster than block
confirmation time. Also, if anybody has ever sent to an address more than
once then those coins are already exposed to a future quantum attacker*. *And
when it comes to early bitcoins, like Satoshi's one million bitcoins, the
public key is directly in the output script and so the coins are already
fully exposed.*
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*John K Clark*
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